Plastics are indispensable, but their pollution is triggering a global environmental crisis. Although many end-of-life catalytic options have involved converting plastics into valuable products, a deep understanding of the relationship between polymer structure and recycling performance is significant and urgently needed. Here, we start with a primer of polymeric chain structures on chemical recycling and discuss the structure–performance relationship between the polymer, catalyst, and catalytic reaction. Specifically, the development and challenges of the chemical re/upcycling of waste PET and polyolefins are discussed in-depth. In addition, we also present some prospects for innovations in catalyst synthesis and reaction engineering on the basis of the structure–performance relationship. The discussion ends with a brief perspective on the future of plastic re/upcycling. Overall, intelligent catalysis design is necessary for incentivizing the chemical recycling of plastics and relieving the burden of waste plastics.

The conversion of CO2 into fuels and feedstock chemicals via photothermal catalysis holds promise for efficient solar energy utilization to tackle the global energy shortage and climate change. Despite recent advances, it is of emerging interest to explore promising materials with excellent photothermal properties to boost the performance of photothermal CO2 catalysis. Here, we report the discovery of MXene materials as superior photothermal supports for metal nanoparticles. As a proof-of-concept study, we demonstrate that Nb2C and Ti3C2, two typical MXene materials, can enhance the photothermal effect and thus boost the photothermal catalytic activity of Ni nanoparticles. A record CO2 conversion rate of 8.50 mol·gNi –1·h–1 is achieved for Nb2C-nanosheet-supported Ni nanoparticles under intense illumination. Our study bridges the gap between photothermal MXene materials and photothermal CO2 catalysis toward more efficient solar-to-chemical energy conversions and stimulates the interest in MXene-supported metal nanoparticles for other heterogeneous catalytic reactions, particularly driven by sunlight.

CO2 hydrogenation has attracted great attention, yet the quest for highly-efficient catalysts is driven by the current disadvantages of poor activity, low selectivity, and ambiguous structure-performance relationship. We demonstrate here that C3N4-supported Cu single atom catalysts with tailored coordination structures, namely, Cu–N4 and Cu–N3, can serve as highly selective and active catalysts for CO2 hydrogenation at low temperature. The modulation of the coordination structure of Cu single atom is readily realized by simply altering the treatment parameters. Further investigations reveal that Cu–N4 favors CO2 hydrogenation to form CH3OH via the formate pathway, while Cu–N3 tends to catalyze CO2 hydrogenation to produce CO via the reverse water-gas-shift (RWGS) pathway. Significantly, the CH3OH productivity and selectivity reach 4.2 mmol g–1 h–1 and 95.5%, respectively, for Cu–N4 single atom catalyst. We anticipate this work will promote the fundamental researches on the structure-performance relationship of catalysts.

The mass production of disposable polyolefin products has led to serious plastic pollution and an imbalance between manufacturing and recycling. Given these challenges, the chemical upcycling of waste polyolefins has attracted extensive attention due to its high efficiency and economic benefits. Herein, we review the development of polyolefin chemical upcycling in heterogeneous catalysis. The status quo of polyolefin recycling is first discussed. We then introduce the advanced strategies for chemical upcycling in the view of different value‐added products and discuss their challenges and prospects. Our in‐depth analysis centers on the catalytic mechanism and the design principle of heterogeneous catalysts. Finally, we outlook the promising directions to facilitate the degradation process via polymer and catalyst design and optimized catalytic engineering. Innovative strategies are expected to promote the chemical upcycling of polyolefins, bringing great promise for the sustainable development of society.